You won’t like my answer which is a suggestion in fact: Simply don’t do it.
Formally x*10^y
is an expression using two operators (in a specific order of preference). In addition the pattern is not limited to integers in the position of y, but is thought to be equivalent to x*EXP(LN(10)*y)
. You also will always need to use the “E-notation” when entering or editing numbers with an “order-of-magnitude-part”. Despite the fact that the “scientific” notation seems not to be internationally specified (by ISO, e.g.) the E-notation is a de-facto standard and can also be used for output/input processes. If you once want to use complex numbers (which are actually represented as text) these will be bound to the E-notation …
Preparing your numerics for prettyprint or for export to a publishing tool, you will have to explicitly convert them into text. You should, however, use the “x” then instead of the asterisk to distinguish the number formally from expressions.
=SUBSTITUTE(TEXT(A1;"0.00E0");"E";" x 10^")
for a value placed in A1 should do if your decimal delimiter is the full stop (otherwise ask again).
There is no way to set specific character formats for parts of a calculated text. You therefore cannot replace the “^” with setting the exponent to superscript.
Having placed the above given formula in B1 you can get back the numeric value by:
=VALUE(SUBSTITUTE(B1;" x 10^";"E"))